Manage your subscription

The dating game

Q&colon; If I was transported in a time machine to an unknown date in Australian history that preceded any European contact on that continent, what would be the best way to determine the date?

A&colon; I’d suggest the following. Take a good look at the Moon. Are the familiar bright ray craters – Copernicus and Tycho – missing? Too bad – you’ve been transported more than one hundred million years into the past, and determining the date is practically impossible.

Is the Moon OK? Great – you’re not as far back in time. Next, take a look at the constellations. Do they look …